In an analog electronic watch such as a wrist watch, the present time can visually be checked with the rotational positions of an hour hand, a minute hand, and a second hand. When such an analog electronic watch undergoes, for example, a shock, a stepper motor which is an inner drive motor may rotate not at a constant step, but by multiple steps in either direction. As a result, the positions of the hands (a second hand, in particular) may be displaced from the position of reference time set in the watch.
For this reason, an electronic watch provided with an optical type hand position detection means has heretofore been proposed (e.g., refer to Patent Document 1). Such optical type hand position detection means detects whether a hand position is displaced when, for example, a shock is applied.
In an electronic watch described in Patent Document 1, an optical type hand position detection means is driven at a reference position (60 minutes in the embodiments), and at a position that is X steps short of the reference position (59 minutes or 59 minutes and 30 seconds, in the embodiments), and a detection value at the time is stored. Thereafter, the detection value thus stored is compared with a predetermined value representing a state where the hand passes the reference position without having a displacement. When the detection value is not equal to the predetermined value, it is determined to be abnormal (a hand position is displaced), and an electric motor (a stepper motor) is fast-forwarded. The detection operation is performed every X steps, and when the latest two values (the predetermined value and the detection value described above) match, the fast-forwarding operation of the electric motor (stepper motor) is stopped to be switched to a normal hand operation.                Patent Document 1: JP 63-36478B        